Wire wrapping machines and guns for attaching interconnection wiring to terminals arranged on a panel or board by solderless wrapped connections are well known in the electronics art. Such machines, while automated to position the wire wrapping bit relative to a selected terminal, require the service of an operator in inserting the wire to be wrapped into the bit for each connection to be made. If in an actual embodiment, the connection panel has a high terminal density, for example, terminals spaced on 0.10 inch centers, it will be appreciated that interconnect wire of very small diameter, such as No. 30 gauge must be used. The wrapping bit is cylindrical and contains a bore to receive the wire to be wrapped. The central or terminal aperture of the bit accommodates the terminal during wrapping. Typically, in the above-mentioned embodiment, the terminal cross section is 0.025 inches square.
Two types of semi-automatic machines involve different wiring gun operations. In the first type, a side-loading wrapping assembly is provided in the gun wherein the sleeve is automatically retracted during loading, thereby exposing the outer surface of the cylindrical bit. In the aforementioned referenced application, there is described and claimed an improved wire holding slot configuration in the bit surface to facilitate both the loading and positioning of the wire to be wrapped. After loading, the sleeve automatically closes over the bit, and both components remain in the same position relative to each other throughout the wrapping cycle.
In contrast to the foregoing, a second type of machine involves a gun wrapping assembly wherein a fixed sleeve encloses a spring-loaded retractable bit throughout the loading and wrapping operation. In this case, the bit is normally front loaded. Since the wire feed opening in the bit is very small, being approximately only one third the diameter of the terminal aperture, it is a tedious task to insert the fine wire into the feed opening, while avoiding the terminal aperture. Thus far, it has been assumed that the operator is able to see the feed opening. However, in many cases, such as with numerical positioning systems, the gun mounting is fixed and the gun is pointed away from the operator, making the front-loading of the gun extremely difficult.
The present invention is directed to this second type of machine, providing in effect, the advantages of a side-loading capability in a fixed-sleeve wiring assembly.